Across
- 4. Gas found in the atmosphere
- 5. They live in nature, others fly, others swim
- 6. Produces oxygen
- 7. Coal, petroleum and natural gas in general
- 9. We breathe it
Down
- 1. An area covered with trees
- 2. The physical environment or organisms
- 3. Plants, animals, mountains, rivers generally
- 4. The weather conditions
- 8. We plant in it